What is a star's main fuel during its lifetime? A. hydrogen B. carbon C. helium D. oxygen

How strongly the planet you're on pulls on you is your

Why can't plants and animals use the nitrogen directly from the atmosphere? A:There is not enough of it in the air. B:Nitrogen gas contains the element in an inert, unusable state. C:They do use it directly from the atmosphere.

A metal rod A and a metal sphere B, on insulating stands, touch each other. They are originally neutral. A positively charged rod is brought near (but not touching) the far end of A. While the charged rod is still close, A and B are separated.

A person on earth (9.8m/s/s) has a mass of 75kg therefore his weight is

A merchant in Katmandu sells you a solid gold 6 kg statue for a very reasonable price. When you get home, you wonder whether or not you got a bargain, so you lower the statue into a measuring cup and measure its volume.

If a bar magnet is broken into two pieces, each of the resulting pieces

Two passengers leave the airport at Kansas City, Missouri. One flies to Los Angeles, California, in 3.5 hr and the other flies in the opposite direction to New York City in 3.5 hr.

What is the term for the basic unit of electric current? The basic unit of electric current is the.

When a sailboat overtakes a powerboat, which vessel is the stand-on vessel?

Both matter and energy can eneter and exit which of the following systems? A. open only B. both open and closed C. isolated only D. both closed and isolated